In the past year, we have completed a prospective study of nosocomial urinary tract infections associated with indwelling urethral catheters at the Latter-Day Saints Hospital. We found that 23% of the patients treated with indwelling catheters acquired bacteriuria even though sterile closed drainage systems were used. Host factors associated with increased rates of infection included advanced age, female sex, and severe underlying disease. Breaks in aseptic technique were frequent and were related to at least 20% of these infections. Our objective now is to develop and evaluate methods for the prevention and control of catheter-induced infections. By intensive surveillance of high-risk catheterized patients, we will evaluate in controlled studies the roles of various active adjuncts to the passive closed drainage system. These methods include: (1) improved aseptic care of these systems by a catheter team supervised by a nurse-epidemiologist; (2) continuous bladder irrigation with anti- bacterial solutions; and (3) prompt short-term use of systemic antimicrobial agents as soon as bacterial colonization is recognized. An important part of these studies will be the follow-up of these patients to compare the costs of prevention with the costs and morbidity of nosocomial urinary tract infections. The following unique features of our project will make the results of these studies especially useful: (1) preliminary work has been completed and a program of continuing surveillance of nosocomial infections is well developed; (2) the different control measures will be evaluated in a single project so that a meaningful comparison of results will be possible; and (3) the site for these studies will be a large community hospital which is one of a group of closely-knit LDS hospitals under a single administration, so that the practicality and general applicability of effective control measures can be rapidly tested in other sister hospitals.